The use of a low carbohydrate diet was a moderately successful treatment for type 1 diabetes before the discovery of injected insulin. The main control of blood glucose was removal of the source, which by and large are carbohydrates.

Later, more drugs are used to control blood glucose in diets heavy in carbohydrates - which metabolize mainly to blood glucose.

It is like the "modern" way of fighting fires. 1) avoid the use of old fashioned fireproof materials, 2) use bigger water pumps, hydrants and hoses to put out the flames of combustion instead.